Sawatch
SnowpackDrew Gibson · Feb 25, 2024 · Sawatch
Weather
Warm and mostly clear with a light breeze below 11,000ft. Above treeline the wind was sustained in the 20mph range from the west.
Snowpack
Warm temps and direct sun have built a thin sun crust on east-facing slopes below about 11,000ft. North-facing slopes near treeline averaged a depth of a little over 1m. Above treeline slopes had obvious signs of wind-loading in the form of smoothly rounded pillows and in some places cornice formation. Multiple areas had cornice failures and many avalanches were observed (coded in other obs). Above and near treeline wind pillows and small test slopes facing easterly and northerly were firm and difficult to cause failures in. Very little cracking was observed and it was isolated to the immediate area around my skis. In a test pit at 11,800ft on a NE facing slope, I found surface hoar buried under soft, slightly wind-affect snow 35cm down. This layer was reactive to tests with moderate compression scores and hard ECT scores (see attached picture). Of note, another layer some large grain facets was failing and propagating 75cm down at the same time as the buried surface hoar. PST scores had failures to END with 30/100 within the surface hoar and 45/100 on the deeper facets. With an added load on the snowpack, it is easy to imagine the surface hoar failing, but more concerning would be the deeper layer 75cm down. On a NE facing slope above treeline I found less snow (~70-90cm) with a buried layer of active surface hoar 50cm down (see attached pit). Northerlies above treeline have a variety of snow cover in this area that is largely dependent on terrain shape. Rounded terrain features like the ridge I was on had little snow at the rollovers but isolated terrain features like gullies and steep rolls near treeline were heavily loaded.